A display simultaneously showing two independent video signals or images, such as a television showing two different channels, is commonly known as a Picture-In-Picture (PIP) display. There are many PIP systems relating to display systems and televisions in particular. Typical PIP systems merge two video signals into a single signal, where, for example, an entire image from a second video signal is shown in a window of a first video signal. The PIP display, therefore, shows the second video image overlaying the first video image. The small scale of the overlaying, or second, image makes viewing its details difficult.
FIG. 1 shows a display of a first video image 10 from a first video signal and a second video image 20 from a second video signal. The first video image 10 may be from a main channel that a viewer wishes to primarily see. The second video image 20 may be from a secondary channel that the viewer merely wishes to superficially monitor. An example of a program on the secondary channel is a financial news show. The images 10 and 20 may temporally change according to the content of the corresponding signal.
In FIG. 2, both video signals are combined as a composite image 30 or PIP display 30, with the second video image 20 over-laying the first video image 10. In FIG. 2, the entire first and second video images 10 and 20 are displayed, although a portion of the first video image 10 is obscured by the over-laying second video image 20, either completely or partially by alpha blending. The area of the first video image 10 that is obscured by the second video image 20 may be reduced if the area of the second video image 20 is made smaller. The conventional art can allow the second video image 20 to be smaller, but unfortunately its concomitant image is smaller and more difficult to see.
Another shortcoming of the conventional art is that a viewer may not want to waste valuable display area on parts of an image that are of no interest. It is highly inefficient to display unwanted parts of a video image at the expense of displaying desired parts.
Accordingly, a need remains for an improved cropped and scaled PIP system and method.